Yamaha FZR750RR OWO1

Yamaha FZR750RR OWO1
Manufacturer	Yamaha
Production	1989
Class	Sportbike
Engine	Four stroke, transverse four cylinder, DOHC, 5 valves per cylinder.
Compression ratio	11.2:1
Top Speed	257.8 km/h / 160.1 mph
Ignition	Transistor controlled digital
Spark Plug	NGK, DR8ES-L
Transmission	6 Speed
Frame	Aluminum, twin spar
Suspension	Front: 43mm Telescopic preload forks, compression and rebound damping adjustment, Rear: Öhlins Monocross preload compression and rebound damping adjustment,
Brakes	Front: 2x 280mm discs 4 piston calipers Rear: Single 177mm disc 2 piston caliper
Front Tire	120/70-ZR17
Rear Tire	170/60-ZR17
Weight	187 kg / 412 lbs (dry),
Recommended Oil	Yamalube 10w-40
Fuel Capacity	23 Liters / 5.2 US gal
Manuals	Service Manual

It could reach a top speed of 257.8 km/h / 160.1 mph.

Engine

The engine was a Liquid cooled, cooled Four stroke, transverse four cylinder, DOHC, 5 valves per cylinder.. The engine featured a 11.2:1 compression ratio.

Drive

Power was moderated via the Wet, multiple discs, cable operated.

Chassis

It came with a 120/70-ZR17 front tire and a 170/60-ZR17 rear tire. Stopping was achieved via 2x 280mm discs 4 piston calipers in the front and a Single 177mm disc 2 piston caliper in the rear. The front suspension was a 43mm Telescopic preload forks, compression and rebound damping adjustment, while the rear was equipped with a Öhlins Monocross preload compression and rebound damping adjustment,. The FZR750RR OWO1 was fitted with a 23 Liters / 5.2 US gal fuel tank. The bike weighed just 187 kg / 412 lbs.

Photos

Overview

Yamaha FZR 750RR OWO1

If this machine looks like a racer, it's because it is! Thinly disguised to make it street  legal, removal of the tax disc, number plate, mirrors, indicators and side stand and fitting some slicks prepares it for the racetrack. Why, then, is it available to the road rider? The reason is relatively simple. The OWOl was built to compete against Honda's RC30 and Bimota's YB4 in World Super- bike racing. In order to campaign a machine in this class certain homologation rules have to be met; these depend on the annual output of motorcycles. If a manufacturer produces more than 100,000 units a year, a minimum of 1,000 of its Superbike contender must be built.

Between 50,000 and 100,000, 500 Superbikes are necessary. Small scale manufacturers (like Bimota) only have to build 200 Super-bikes to be eligible. In Yamaha's case they have to build 1,000, which means that some go on sale, albeit at huge expense, for road use. They come sparsely equipped for the task. The OWOl isn't a road bike, it's a sports-stiff, high-revving, factory racer. As standard, it comes pretty competitively set up for the track. An expensive racekit is available to further hone its fiery performance and turn what's already a lean and purpose-built beast into a real short-fuse, speedball racetrack weapon. Apart from the wonders of five-valve technology and inclined cylinders, the OWOl has little in common with the popular FZ750 roadster. Instead it's cobbled together using lessons learnt from the rare and precious YZF750 Genesis, the factory endurance racer, with lots of FZR1000 bits and knowhow thrown in for good and plentiful measure.

The engine is incredibly oversquare and short-stroked. Every part of its assembly is dedicated to getting the biggest and most efficient bangs for your money. It sucks through forward-facing fresh air ducts in the fairing, mixing and feeding the gas through large flat-slide 38mm Mikunis. It has big' valves and big, hand-finished ports. Lightweight, short-skirt, stepped-top pistons with large valve cutaways ride on titanium con rods and compress the gas to 11.2:1 (with the racekit this is upped to 13.5 or more). At the same time as it controls ignition timing. Providing a fat spark, an eight-bit microprocessor decides when to activate a servo motor operating a butterfly valve in the collector of the stainless steel four-into-one exhaust system. As on the FZR1000, this exhaust valve (EXUP) compensates for losses in the mid-range that are inevitable in any engine developed for maximum power and torque. The EXUP rotary valve has to close off up to 70 per cent of the exhaust and operate in temperatures of up to 700-degrees C. but it certainly works.

What should be an essentially peaky, sky-high, rev-happy motor is actually endowed with a useful, long flat spread of torque. It can be ridden from 0-5000rpm with fast response and the delivery is crisp, flexible and smooth. It reserves its best power for between 8000 and 13,500rpm, quite a wide range of meaty acceleration. In its stride, it peaks at about 12,000rpm. Translate that through six close-ratio gears into road speed and in top the bike clocks 162mph. A race-kitted version, lighter and more powerful will be tall-geared for over 170mph.

With the cylinders angled forward at40-degrees (instead of the 45-degrees of the FZ750 road bike), Yamaha's chassis designers took full advantage of the layout and assembled a short, stiff frame, a short wheelbase, fast steering geometry and lots of Ground Clearance. The deep section aluminum Deltabox frame is obviously rigid and the swing-arm is beautifully crafted. Suspension front and back is by top notch Öhlins units which are multi-adjustable for individual ride preferences. The huge brakes sport Nissan four-piston racing calipers and 320mm discs.

Generally, the bike is very stable on the power, though the steering isn't as quick and nervy as racers typically like. Although the bike is clearly competitive weight-wise, in standard trim it has to be wrestled with, needing a firm grip and a lot of rider input. Naturally, it wouldn't be a racer unless just about every part of its handling performance could be changed to suit the rider. The OWOl has more power, performance and commitment than the road rider could ever need.

Make Model	Yamaha FZR 750RR OWO1
Year	1989
Engine Type	Four stroke, transverse four cylinder, DOHC, 5 valves per cylinder.
Displacement	749 cc / 45.7 cu-in
Bore X Stroke	72 x 46 mm
Cooling System	Liquid cooled,
Compression	11.2:1
Lubrication	Wet sump
Engine Oil	10W/40
Exhaust	Alloy muffler
Induction	4X 38mm Mikuni carbs
Ignition	Transistor controlled digital
Spark Plug	NGK, DR8ES-L
Starting	Electric
Max Power	121 hp / 88.3 kW @ 12000 rpm
Max Power Rear Tire	108.8 hp @ 12500 rpm
Max Torque	7.2 kgf-m / 69,6 Nm @ 9000 rpm
Clutch	Wet, multiple discs, cable operated
Transmission	6 Speed
Final Drive	Chain
Frame	Aluminum, twin spar
Front Suspension	43mm Telescopic preload forks, compression and rebound damping adjustment,
Rear Suspension	Öhlins Monocross preload compression and rebound damping adjustment,
Front Brakes	2x 280mm discs 4 piston calipers
Rear Brakes	Single 177mm disc 2 piston caliper
Front Tire	120/70-ZR17
Rear Tire	170/60-ZR17
Dry Weight	187 kg / 412 lbs
Wet+ Weight	215 kg / 474 lbs
Fuel Capacity	23 Liters / 5.2 US gal
Consumption Average	16.2 km/lit
Braking 60 - 0 / 100 - 0	12.7 m / 35.3 m
Standing ¼ Mile	10.7 sec / 205.8 km/h
Top Speed	257.8 km/h / 160.1 mph
Road Test	Bike Magazine Moto.Revue 1989 Motorrad YB4 vs FZR750R Motosprint Group Test 1990 Performance Bike Yamaha OWO1 vs Honda RC30

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